On 06/06/2016 08:28 AM, Liam Proven wrote:
> AIUI -- not sure -- the 720 kB *format* was mostly used on 5.25"
> DS/DD 80-track disks, no?
I'm not sure what you consider 720K, so the question is hard to answer.
On MS-DOS machines? Perhaps, but there weren't a lot of them in
comparison to the IBM PC and its ilk.
But IBM offered the "slimline" 3.5" drive pretty early on; see the O&A
section on it--and it was indeed a DD "720K" formatted application.
(FWIW, the earliest drives on the 5150 were used as 160K and 320K format
implementors.)
>> If a good 150RPM ED drive were to have been readily available, then
>> 2.8M could have been retrofitted to all 1.4M systems, including
>> Amiga, etc. But would that, and the Barium-Ferrite disks have been
>> worth it for just twice the capacity?
>> Wouldn't they have got much cheaper if every cloner had used them?
Slow-spinning floppy drives are at best, a kludge. Like a lot of other
physical phenomena, the energy induced in a read/write head is roughly
proportional to rotation speed. Low speed -> low output. So not such a
good idea. I liked the idea of the 600 RPM 3.5" Sony drives.
--Chuck